The invention is based on a device of the generic type of the main claim. A device of this kind is already known (German Offenlegungsschrift No. 3,234,468), but in this there is the disadvantage that the complete opening of the control orifice, starting from a control orifice opening forming an emergency-running cross-section, is attainable only after traversal of the maximum control path of the throttle member, for which the maximum control current is required to excite the positioning motor. A device of this kind is used to regulate the idling speed of internal combustion engines in order, with the minimum possible speed, to achieve favorable consumption figures and emission values. Here, the lowest possible idling speed is dependent on various operating conditions of the internal combustion engine, for example on the load condition, the external temperature and the engine temperature or the power requirement of systems which are driven by the internal combustion engine, for example an air conditioning system. By virtue of this and in particular at very low starting temperatures of the internal combustion engine, the supply voltage delivered by the battery of the motor vehicle falls and the positioning motor of the idle-regulation device cannot be supplied with the necessary current to adjust the throttle member, precisely in this operating condition, to a position which opens the control orifice completely.
In addition, in the known device there is the danger that if the spring element breaks and the positioning motor is excited, the control orifice will be opened completely by the throttle member and the operation of the internal combustion engine will be influenced in an undesirable manner or even endangered.